Principles of Filtration

Mechanical air filters remove particles from the air stream because particles come into contact with the surface of fibres in the filter media and adhere to the fibres. The mechanisms by which the particles come into contact with the fibres in the filter media are Straining (sieving), Interception, Diffusion, Inertial seperation and Electrostatic attraction. The first of these mechanisms applies mainly to mechanical filters and is influenced by particle size. Electrostatic filtration is obtained by charging the media as a part of the manufacturing process.